Antelope Complex
Fire Behavior Assessment Report
fire burning across site 2 at night
Prepared 7/14/2007
Fire Behavior Assessment Team
Jo Ann Fites, Team Leader/Technical Specialist
Mike Campbell, Operational Lead/Technical Specialist
Alicia Reiner, Technical Specialist
Todd Decker, Technical Specialist
Carol Ewell, Technical Specialist
Gail Bakker, Technical Specialist
7/23/2007
Fire Behavior Assessment Team
2
Contents
Executive Summary
Introduction
Objectives
Applications
Approach
Fire Behavior Measurements and Observations
Vegetation and Fuels Measurements
Findings
Overall
Vegetation, Fuels, Fire Behavior and Effects
Post Fire Consumption and Immediate Effects
Appendix A: Detailed pre- and post-fire comparisons and photos
By site
Appendix B: Temperature Graphs
Appendix C: How to Order the FBAT team
7/23/2007
Fire Behavior Assessment Team
3
Executive Summary
Introduction
Wildfire suppression and wildland fire use fire management are dependent upon good fire behavior and
resource effects predictions. Existing fire behavior and resource effects prediction models, such as
FsPro and FARSITE are based upon limited data from fire in the field, especially quantitative data. The
Fire Behavior Assessment Team (FBAT) collects data to improve our ability to predict fire behavior and
resource effects in the long-term and provides short-term intelligence to the wildland fire use managers
and wildfire incident management teams on fire behavior-fuel and effects relationships. Increasing our
knowledge of fire behavior is also important to fire fighter safety – the more we know the more we can
mitigate hazards and prevent accidents. The team also collects other information on fire fighter safety,
such as convective heat in safety zones as opportunities arise.
This report contains the results of the assessment of fire behavior in relation to fuels, weather and
topography, and fire effects to resources in relation to fire behavior on the Wheeler fire of the Antelope
Complex.
Objectives
Our first objective was to quantify fire behavior in relation to fuels and weather for a variety of fuel
conditions, especially through areas treated for fuel hazard reduction. Our second objective was to
conduct a rapid assessment of fire behavior across the fire in relation to the time of day, suppression
activities, fuel treatments and vegetation conditions.
Two different approaches were used. For the first objective we gathered detailed, quantitative data on
pre-fire fuels, fire behavior and post-fire conditions. For the second objective, we conducted a rapid, on
the ground survey, of immediate post-fire evidence of fire behavior (i.e. scorch, crown consumption,
needle freeze) and interviewed firefighters present.
Accomplishments
Quantitative pre-fire fuels data were collected at 18 sites. Fire behavior, pre-fire fuels and post-fire
conditions were measured at 9 of the 18 sites that burned. Amongst the 18 sites sampled, 13 had
received some type of treatment ranging from prescribed fire to thinning and burning, and selective
harvest/thinning. Direct observation of the fire behavior and suppression in relation to the treatment
sites were made. Many of the unburned sites that had previously been treated were utilized for
suppression activities that resulted in the sites not burning. The sites encompassed a variety of
vegetation and fuel types. This included eastside yellow pine (Jeffrey and/or ponderosa pine) with grass
or bitterbrush and manzanita or mahala mat understories and transitional (between eastside and
westside) forests comprised of various mixtures of yellow pine, white fir and Douglas-fir. The mixed
transitional forests had various understories with the most prevalent plants including tobacco leaf
ceanothus, greenleaf manzanita, mahala mat, bitterbrush, snowberry and various grasses. One mixed
white fir and lodgepole pine stand was sampled.
For the rapid assessment, 61 rapid plots were established, including photos, GPS locations, severity
ratings for the tree canopy and soils and evidence of fire behavior (i.e. needle freeze). A treatment
history layer was obtained from the Plumas National Forest and interviews with firefighters that staffed
the fire from initial attack to when the team arrived were conducted.
7/23/2007
Fire Behavior Assessment Team
4
Introduction
Introduction
Wildfire suppression and wildland fire use fire management are dependent upon good fire behavior and
resource effects predictions. Existing fire behavior and resource effects prediction models, such as
FsPro and FARSITE are based upon limited data from fire in the field, especially quantitative data. It is
difficult to accurately predict fire behavior in the outside environment based upon laboratory data,
limited experimental data on prescribed burns or broad field observations. The Fire Behavior
Assessment Team (FBAT) collects data to improve our ability to predict fire behavior and resource
effects in the long-term and provides short-term intelligence to the wildland fire use managers and
wildfire incident management teams on fire behavior-fuel and effects relationships. Increasing our
knowledge of fire behavior is also important to fire fighter safety – the more we know the more we can
mitigate hazards and prevent accidents. The team also collects other information on fire fighter safety,
such as convective heat in safety zones as opportunities arise. (See Appendix C for information on the
Fire Behavior Assessment Team).
This report contains the results of the assessment of fire behavior in relation to fuels and weather, and
immediate fire effects in relation to fire behavior on the Wheeler fire of the Antelope Complex.
Objectives
Our objectives were to characterize fire behavior in relation to fuels and weather for a variety of
conditions, in particular for areas that had been treated for hazardous fuel reduction. A key
consideration was which sites could be measured safely given access and current fire conditions.
Applications
The information will be shared with firefighters to improve situational awareness, managers to improve
predictions for fire planning, and scientists for improving fire behavior models. A proposal will be
submitted to the Joint Fire Science Program to conduct further detailed analysis and more formal
publication of the information.
Approach
Pre- and post-fire fuels and fire behavior measurements were made at sites throughout the fire. Sites
were selected to represent a variety of fire behavior and vegetation or fuel conditions. Priority was on
sites that would most likely receive fire. A rapid assessment of fire severity and effects was conducted
across the portions of the fire that had burned.
Quantitative Fire Behavior Measurements and Observations
At each site, sensors were set up to gather information on fire behavior including: rate of spread, fire
type, flamelength, and flaming duration. Temperature and wind speed were also measured at most
sites.
Flamelength and Flaming Duration
Flamelength was determined from video and sometimes supplemented by tree height or char. If
crowning occurred above the view of the camera, then tree height was used to estimate the minimum
flamelength. Flaming duration was based on direct video observation and when temperature was
measured, from those sensors as well.
7/23/2007
Fire Behavior Assessment Team
5
Figure 1. Installing fire behavior sensors and measuring fuels at one of sites.
Fire Type
Fire type was determined from video as well as post-fire effects at each site. Sites where there was
complete consumption of needles in the crowns was classified as crown fire.
Rate of Spread and Temperature
Rate of spread was determined by video analysis and rate of spread sensors (RASPS) which have a
piece of solder attached to a computer chip (buried in the ground) that records the date and time when
the solder melts or from thermocouples that measure temperature. In addition, on most sites,
thermocouples attached to Campbell Scientific data loggers were also used for rate of spread. The
distance and angle between RASPS or thermocouples were measured and the Simard (1977) method
of estimating rate of spread using trigonometry was applied.
Vegetation and Fuel Measurements
Vegetation and fuels were inventoried before the fire reached each site and then again within a few
days after fire had burned through. Consumption and fire effects (i.e. scorch) were inventoried after
burning. Mortality was not determined for trees, since mortality can be delayed for some time after the
fire, and is not possible to determine immediately post-fire.
Crown Fuels and Overstory Vegetation Structure
Tree density, basal area, tree diameters, tree heights and canopy base heights were measured by
species for each site. A relaskop was used for overstory and pole tree plots. Heights were measured
with an impulse laser. Diameters were measured with a Biltmore stick. The Fire Management Analyst
program, based on the Forest Vegetation Simulator (FVS) program was used to calculate canopy bulk
density, canopy base height, tree density and basal area.
Fuels were measured along a 50 foot transect at each site, in view of one of the video cameras.
Surface fuels were inventoried with a Brown’s planar intercept. Understory vegetation and live
7/23/2007
Fire Behavior Assessment Team
6
fuels were estimated occularly in a 1 meter wide belt plot along the Brown’s transect. The
Burgan and Rothermel (1984) fuels photo series was used in order to estimate tons per acre of
live fuels.
Foliar Moisture and Weather
Live foliage was collected on each plot and oven dried to determine foliar moisture. Weather
data was downloaded from the Pierce permanent remote automated weather station (RAWS),
8 miles to the northwest of the fire.
Findings
Overall
Fire behavior and post-fire data were collected at 9 sites that burned (Figure 2). Nine additional sites
did not burn due to suppression actions. Sites were grouped into dominant vegetation types and
whether they had recent prescribed fire to summarize the data (Table 1). Four vegetation types were
sampled including: yellow pine/grass, meadow border; yellow pine/shrub; yellow pine- Douglas-fir –
white fir; and white fir- lodgepole pine.
A variety of fire behavior was measured across the sites, although most was surface fire. On several of
the sites there was torching, particularly where concentrations of surface fuels (particularly downed
logs) or tree crowns extended to the ground or dense patches of seedlings or saplings occurred.
7/23/2007
Fire Behavior Assessment Team
7
Table 1. Vegetation types assigned to each site and used to group data.
Description
Site
yellow pine/grass meadow border, untreated
11,17
18
Untreated, dense yellow pine with light grass understory next to meadow.
yellow pine/grass meadow border, treated
Yellow pine with light grass understory next to meadow. Treated with prescribed fire.
yellow pine/shrub, untreated
15
Untreated open pine with bitterbrush understory.
12
yellow pine/shrub, treated
Open yellow pine with mixed shrub understory of bitterbrush, Greenleaf manzanita and
mahala mat. Boulders throughout site. Treated with selective harvest/thin.
Yellow pine plantation with dense tobacco leaf ceanothus understory. Thinned plantation.
Unburned.
14
2
8
Mature Yellow pine with occasional white fir, greenleaf manzanita and grass understory.
Treated with understory/midstory thinning.
yellow pine-Douglas-fir-white fir, treated
Open yellow pine stand with scattered Douglas-fir and white fir. Bitterbrush and greenleaf
manzanita understory. Treated with selective harvest/thin.
Open Douglas-fir mixed conifer. Treated with selective harvest and pile burning.
10
Shrubby young Douglas-fir mixed conifer with an understory of tobacco leaf ceanothus,
bitterbrush, greenleaf manzanita, mahala mat, grass and mule’s ears. Treated with selective
harvest and thinning.
3
Open pine with scattered white fir. Understory with tobacco leaf ceanothus, greenleaf
manzanita and mahala mat. Treated with thinning and burning. Unburned.
19
4
5
9
1
7
13
6
Very open yellow pine and incense cedar with scattered Douglas-fir. Greenleaf manzanita
and bitterbrush in the understory. Treated with selective harvest/thin. Unburned.
Yellow pine and white fir with sparse herbaceous and grassy understory. Treated with
thinning and burning. Unburned.
Yellow pine overstory with scattered white fir midstory. Patchy understory of greenleaf
manzanita, bitterbrush, mahala mat and grass. Treated with selective harvest/thin.
Unburned.
Douglas-fir mixed conifer with understory of Greenleaf manzanita, mahala mat and grass.
Treated with selective harvest/thin. Unburned.
Yellow pine and white fir with understory of tobacco leaf ceanothus and grass. Treated with
thin/burn. Unburned.
yellow pine-Douglas-fir-white fir, untreated
Untreated Douglas-fir mixed conifer/in a draw with numerous boulders and understory of
tobacco leaf ceanothus, Scouler’s willow and thimbleberry. Unburned.
white fir-lodgepole pine/snowberry
Untreated dense young white fir and lodgepole pine with snowberry in the understory.
Unburned.
7/23/2007
Fire Behavior Assessment Team
8
Figure 2. Map with locations of sample sites.
(See associated antelope_map.pdf file that is attached.)
Vegetation, Fuels, Fire Behavior and Effects
Data on pre-fire vegetation structure (tables 2 and 3), pre-fire live fuels (table 4), pre-fire surface fuels
(table 5), fire behavior (table 6), post-fire consumption of surface fuels (table 7) and immediate post-fire
effects (table 8) were summarized.
Pre-fire Vegetation Structure and Fuels
Vegetation and fuels varied amongst the sites (Tables 2, 3, 4, 5). Overall canopy covers were lowest in
treated sites but mostly were less than 50% across all plots. Most sites had well developed shrub
layers.
Table 2. Canopy cover by lifeform by site. Canopy cover is based on ocular estimates of cover
classes. Classes were: <1%, 1-9%, 10-24%, 25-49%, 50-74%, >75%. Covers are based on
overlapping cover of individual shrubs (can add up to more than 100%).
Site
11
17
18
15
12
19
14
2
8
10
3
4
5
9
1
7
13
6
7/23/2007
Canopy Cover by Lifeform (%)
Tree
Seedlings
Shrubs
Herbs
Overstory
yellow pine/grass meadow border, untreated
50-60
1
0
2
>60
0
0
2
yellow pine/grass meadow border, treated
50
0
22
2
yellow pine/shrub, untreated
20-30
0
55
2
yellow pine/shrub, treated
20
0
>60
4
40-50
0
3
8
40-50
0
>60
7
yellow pine-Douglas-fir-white fir, treated
20-30
0
43
1
20-30
1
5
5
5
5
51
1
20
0
30
4
0-15
1
52
3
40
0
0
0
0-30
7
17
22
30-40
1
41
2
30
0
10
11
yellow pine-Douglas-fir-white fir, untreated
30-40
9
39
3
white fir-lodgepole pine/snowberry
70
5
5
0
Fire Behavior Assessment Team
Grasses
11
10
12
11
12
25
0
1
5
6
5
33
0
0
25
25
3
0
9
Table 3. Pre-fire forest structure calculated using FMA (Fire Management Analyst), based
on algorithms from the Forest Vegetation Simulator. California wildlife habitat relations
types (CWHR) computed with GAMMA, a custom program used for the Sierra Nevada
Forest Plan Amendment EIS. CWHR codes as follows: 2-average tree diameter 6-11”
DBH, 3-average diameter 12-23” DBH, 4-average diameter >24” DBH. Density classes: S10 to 24% tree cover, P – 25 to 39% cover, M – 40-59% cover, D- >60% cover.
Site
11
17
18
15
12
19
14
2
8
10
3
4
5
9
1
7
13
6
7/23/2007
California
Basal Area
Average
Canopy
Wildlife
(ft2/ac)
Stand
Ceiling
Habitat
Height (ft)
Height (ft)
Relations
Types
(CWHR)
yellow pine/grass meadow border, untreated
5M
24
53
108
5/3D
33
50
102
yellow pine/grass meadow border, treated
4/5M
16
53
92
yellow pine/shrub, untreated
5/2P
22
18
59
yellow pine/shrub, treated
4S
15
54
83
3M
7
36
54
2M/P
1
12
17
yellow pine-Douglas-fir-white fir, treated
5P
28
49
84
3P
2
36
44
3S
8
36
48
4S
11
56
85
5/3S
16
74
92
5/4P
14
60
91
4P
8
49
84
5/4P
18
30
92
4/5P
10
39
57
yellow pine-Douglas-fir-white fir, untreated
3/2P
7
44
84
white fir-lodgepole pine/snowberry
2/4P
9
15
89
Fire Behavior Assessment Team
Canopy
Bulk
Density
(kg/m3)
Canopy
Base
Height
(ft)
0.14
0.17
15.0
13.0
0.02
6.0
0.12
2.0
0.21
0.33
0.08
11.0
na
1.0
0.07
0.09
0.04
0.06
0.10
0.09
0.14
0.09
0.16
13.0
na
4.0
7.0
14.0
16.0
9.0
na
7.0
0.14
2.0
0.68
7.0
10
Table 4. Live and dead fuel loading of lifeforms by site before the Wheeler fire of the Antelope Complex.
Understory fuels were calculated using the Burgan and Rothermel (1984) photo-series method.
Live &
Percent
Percent live
Live & Dead
Percent live
Percent live
Dead
live
herbs
Shrub,
shrubs
seedlings
%
%
%
Grass,
grasses
Seedlings
%
Herb
(tons/acre
(tons/acre)
Site
Yellow pine/grass meadow border, untreated
11
0.03
30
83
0.05
0
100
17
0.03
43
70
0.00
0
0
yellow pine/grass meadow border, treated
18
0.03
45
80
4.32
49
0
yellow pine/shrub, untreated
15
0.07
60
60
7.30
55
0
12
19
14
0.02
0.14
0.02
2
8
10
3
4
5
9
1
7
0.00
0.01
0.02
0.05
0.07
0.00
0.14
0.02
0.24
13
0.01
6
0.00
7/23/2007
yellow pine/shrub, treated
25
40
19.45
20
53
0.01
30
0
13.18
yellow pine-Douglas-fir-white fir, treated
90
80
8.14
20
65
0.01
30
60
5.25
40
63
0.39
37
85
10.43
0
0
0.00
28
43
2.72
60
50
1.58
0
50
0.83
yellow pine-Douglas-fir-white fir, untreated
48
95
7.18
white fir-lodgepole pine/snowberry
0
0
0.54
Fire Behavior Assessment Team
57
85
45
0
0
0
58
90
70
93
53
0
75
93
83
0
100
20
0
100
0
95
100
0
59
80
90
70
11
Table 5a. Litter and duff pre- and post-fire. Calculated from litter and duff depth using van Wagtendonk et al. (1998).
Site
7/23/2007
Pre-fire
Litter
Duff
Depth
Depth
(in)
(in)
11
17
0.6
2.4
0.8
1.2
18
1.3
0.6
15
1.2
0.8
12
19
14
0.4
0.9
1.0
0.8
0.8
0.0
2
8
10
3
4
5
9
1
7
2.3
0.2
0.6
1.2
0.6
1.2
1.2
1.0
1.2
1.6
1.8
0.4
1.2
0.2
1.0
2.4
1.6
0.0
13
1.2
2.4
6
0.6
1.8
Post-fire
Litter
Duff
Litter
Duff
Litter
Weight
Weight
Depth
Depth
Weight
(tons/ac) (tons/ac)
(in)
(in)
(tons/ac)
yellow pine/grass meadow border, untreated
1.6
20
0.6
0.0
1.6
9.7
48
0.0
0.0
0.2
yellow pine/grass meadow border, treated
5.3
13
0.2
0.3
0.8
yellow pine/shrub, untreated
31
0.0
0.0
0.0
4.9
yellow pine/shrub, treated
13
1.6
0.2
0.6
0.8
25
0.0
0.0
0.0
3.6
10
*
*
*
4.0
yellow pine-Douglas-fir-white fir, treated
60
0.0
0.0
0.0
9.3
21
0.0
0.0
0.0
0.8
12
2.4
0.2
0.1
0.8
24
*
*
*
4.9
12
*
*
*
2.4
34
*
*
*
2.4
60
*
*
*
4.9
43
0.0
0.0
0.0
4.0
10
*
*
*
4.9
yellow pine-Douglas-fir-white fir, untreated
60
*
*
*
4.9
white fir-lodgepole pine/snowberry
34
*
*
*
2.4
Fire Behavior Assessment Team
Duff
Weight
(tons/ac)
Consumption (%)
Litter
Duff
4.8
0.0
0%
100%
76%
100%
6.4
85%
50%
0.0
100%
100%
0.8
0.0
*
50%
100%
*
94%
100%
*
0.0
0.0
2.8
*
*
*
*
0.0
*
100%
100%
67%
*
*
*
*
100%
*
100%
100%
77%
*
*
*
*
100%
*
*
*
*
*
*
*
12
Table 5b. Pre and post-fire surface fuel loading and consumption calculated from Brown’s
planar transects.
Site
1 hour
11
17
0.0
0.0
18
0.1
15
0.0
12
19
14
0.0
0.0
0.1
2
8
10
3
4
5
9
1
7
0.0
1.5
0.4
0.3
0.1
0.1
0.0
0.3
1.2
13
1.2
6
0.8
Pre-fire Fuels
100
total <
hour
3" fuels
10 hour
1000
hour
rotten
1000
hour
sound
yellow pine/grass meadow border, untreated
0.0
0.0
0.0
0.0
0.0
1.3
0.0
1.3
12.5
2.5
yellow pine/grass meadow border, treated
1.2
3.6
4.9
1.8
0.0
yellow pine/shrub, untreated
0.3
0.0
0.3
0.0
0.0
yellow pine/shrub, treated
0.0
2.4
2.5
0.0
0.0
1.8
3.6
5.5
0.0
0.0
1.2
6.1
7.4
9.2
1.4
yellow pine-Douglas-fir-white fir, treated
1.8
1.2
3.1
11.1
3.6
1.8
1.2
4.6
0.0
0.0
2.7
0.0
3.2
3.9
20.4
1.2
1.2
2.7
0.0
3.2
0.6
1.2
1.9
2.1
8.2
0.9
2.4
3.4
5.7
12.4
0.3
2.4
2.8
3.5
9.9
0.0
1.2
1.5
21.9
3.4
1.8
1.2
4.2
0.0
0.0
yellow pine-Douglas-fir-white fir, untreated
3.4
8.1
12.7
3.9
17.0
white fir-lodgepole pine/snowberry
1.8
4.8
7.5
0.0
11.0
Consumption (%)
< 3"
> 3"
fuels
fuels
100%
100%
na
100%
90%
100%
0%
na
99%
70%
*
na
na
*
100%
100%
85%
*
*
*
*
*
*
100%
*
*
*
*
55%
*
*
*
*
*
*
Weather and Fuel Moisture
Weather data was summarized from the nearby Pierce RAWS station, which is located 8 miles
to the west of the fire. Additional RAWS stations were set up on the incident closer to the fire
behavior measurement sites, but these were installed after the sites had burned.
Fuel moisture samples were gathered but the oven malfunctioned and the data were not
representative.
7/23/2007
Fire Behavior Assessment Team
13
Figures 3a, 3b. Summary of weather data from the Pierce RAWS weather stations during the
times when sites burned. Weather at the fire behavior plots may differ because of the distance
of this RAWS from the sites. Site specific temperatures and windspeeds were taken on many of
the sites.
Pierce RAWS
Hourly Relative Humidity
60%
Relative Humidity
50%
40%
30%
20%
10%
0%
7/7/2007
7/8/2007
7/9/2007
Date
7/23/2007
Fire Behavior Assessment Team
7/10/2007
14
Pierce RAWS
Hourly Temperatures
100
95
90
Temperature (
85
80
75
70
65
60
55
50
7/7/2007
7/8/2007
7/9/2007
Date
7/23/2007
Fire Behavior Assessment Team
7/10/2007
15
Fire Behavior and Fire Effects
The descriptions of fire behavior and effects below are based on an initial rapid assessment.
Videos were assessed visually for now, and the estimates might change with future more
detailed digital analysis of the imagery.
Sites Unburned Due to Suppression
Half of the sites where fire behavior equipment was set up did not burn due to suppression
actions (Table 6). This included suppression of spot fires, direct suppression and indirect line
placement (Figure 4).
Figure 4. Bulldozer going through site 1, tripped camera wire and site did not burn due to line
construction.
7/23/2007
Fire Behavior Assessment Team
16
Table 6. Description of suppression actions for sites that did not burn.
Description of sites that did not burn and site 10 where fire behavior was substantially
modified by suppression actions (Site 10)
Site
Treated Sites Used In or Affected by Suppression Operations
1
4, 7
10
3,5,6,9
13, 14
Unburned. Initially, spot was contained by a bulldozer line adjacent to the site along the 27N59
road. Later the fire progressed north and across the 27N59 road, but this portion of the treated
area never burned.
Unburned. Site 7 unburned due to direct line built below the plot, to the east of the 28N01 road.
Site 4 had bulldozer line cut below and above the fire behavior sensors through a treated area.
Below the site was direct attack and above the site was a secondary fire line.
Site burned at low intensity on its own, but was affected by suppression. Camera was triggered
by dozer operations at 2200 hours and it was apparent that helicopter water drops were made in
vicinity. Burned as a slow, low intensity backing fire at night.
Treated and Untreated Sites where Fire Never Made it due to Strategy and Tactics
Fire never made it to these sites north of the 27N36 road due to successful suppression below.
Site 6 was untreated; the other sites had recent or older treatments.
Untreated Sites Affected by Suppression
Sites unburned due to direct attack (hand and dozer line) below and to east of sites, was
planned to be in part of large burn operation along 26N46 and 99 roads but change of tactics.
Site 10, Fire behavior substantially modified by suppression
Site 10 was in the interior of the fire, below road 27N36. At the time the fire behavior equipment
was placed and pre-fire fuels were measured, there was fire on three different sites of the
sample site during the early evening. Later that evening a bulldozer went up into the edge of the
plot, restricting fire spread from two directions. There were also apparently water drops from a
helicopter either that evening or the following morning. The site burned with low intensity and
with some unburned patches remaining due to suppression actions. The camera ran out of
video tape (90 minutes) before the fire entered the site and there are no pictures.
Sites that Burned
The team arrived the evening of July 6th, when very active fire behavior occurred, including
development of a pyrocumulus that collapsed and resulted in an extensive area of high intensity
fire that moved rapidly. The associated rapid assessment report contains a description of the
fire behavior during the first two days of the fire when fire progression was most rapid and fire
intensity the greatest.
Of the 9 sites that burned, most burned as low intensity surface fires, many at night (Table 7,
Figures 5-7). These were all placed and burned from July 7th through 12th. There were several
that burned as moderate or high intensity surface fires with torching. On all of the sites, where
concentrations of surface fuels, shrubs, logs, or tree seedlings were present, the fires burned
more intensely and there was high fuel consumption. Where tree crowns were low to the
ground or where tree crowns were above ladder fuels or logs, torching occurred. All but one of
these sites burned in a green island in the interior of the fire.
7/23/2007
Fire Behavior Assessment Team
17
Figure 5. Site 2, burned as head fire against the wind at night.
Figure 6. Site 18, burned as low intensity backing fire through area treated with prescribed fire.
Figure 7. Pictures of understory torching at site 19.
7/23/2007
Fire Behavior Assessment Team
18
Table 7. Fire behavior measurements and observations by site that burned.
Fire Type
Site
2
low intensity
surface fire at
night, head fire
upslope
against the
wind
low intensity,
backing
surface fire at
night
8
11
low intensity,
backing
surface fire at
night
low intensity
surface fire
Untreated Sites Affected by Suppression
Flamelength
Rate of Spread
Flame Duration and
(ft)
(chains/hr)
Temperatures (0F)
Burned in interior island
10 to 20 until it
2800 F maximum ,
combustion >90
hit the top of the
minutes (length of
plot and slowed
down to 0.5 to 1 tape), combustion for
21 hours from
consumption of logs
1 to 4’; but 6’ to
0.5
23’ when it ran
up fir trees with
crown bases to
the ground
<1'
0.2-0.5
3700 F maximum
3’ to 5’
15
17
18
19
low intensity,
backing
surface fire
high intensity
surface fire
with torching
in midstory
and overstory
9000 F maximum, fire
extended for >1 day
slowly in a patchy
pattern through the
plot
none measured
<1 to >4'
variable from
<0.1 to 0.5
4 to 6'
3 to 7
0.5 to 1'
0.1 to 0.5
5900 F maximum, 10
hours of combustion
including burning logs
0.5 to 1'
1
none measured
4 to 30'
sensors
malfunctioned
none measured
12
moderate
intensity
surface fire
with some
torching in
midstory trees
low intensity
surface fire at
night
Comments
at 03:50 in the
morning
fuels were patchy and
discontinuous, no
video of the fire with 2
tapes because of
slow spread
Post-fire Consumption and Immediate Effects
The fire effects that we measured and observed post-fire are immediate. The effects reported
here include fuel consumption, crown scorch and consumption by vegetation layer (overstory
tree, midstory tree, shrub, grass) and changes in soil color and cover (Tables 8 and 9). It is not
possible to determine tree mortality or mortality of understory plants that may resprout so soon
after the fire.
7/23/2007
Fire Behavior Assessment Team
19
Table 8. Substrate severity rating (National Park Service).
Site
Very high
High
Moderate
Low
Unburned
(1)
(2)
(3)
(4)
(5)
yellow pine/grass meadow border, untreated
11
30
30
30
10
17
10
30
60
yellow pine/grass meadow border, treated
18
10
20
70
yellow pine/shrub, untreated
15
5
30
30
35
yellow pine/shrub, treated
12
10
20
50
20
19
30
60
10
yellow pine-Douglas-fir-white fir, treated
2
5
70
20
5
8
30
70
10
15
25
5
40
National Park Service, substrate severity ratings: 1- very high, white ash, some discoloration of
soil; 2 – high, gray and black ash; 3 – moderate, ash and some patches of charred litter or duff;
4 – low severity, charred litter and some unburned litter and duff remain; 5 – unburned.
Table 9. Summary of immediate post fire effects per site. Mortality is not included, since
survival cannot be determined immediately post-fire. Trees that are scorched can survive. Data
below shows torch, where needles are consumed, and scorch, where needles are brown
but not consumed. Results below are based upon a rapid analysis of measured crown scorch
and torch. Detailed data by individual tree was recorded but not summarized quantitatively at
this time.
Understory consumption
Site
Grass/herb
11
100%
17
100%
18
100%
15
70%
12
19
80-100%
100%
2
8
100%
100%
10
0-100%
7/23/2007
Midstory
Tree
Scorch
Torch
Shrubs
seedlings (%crown) (%crown)
yellow pine/grass meadow border, untreated
none
100%
none
none
none
50-100%
none
yellow pine/grass meadow border, treated
100%
none
none
none
yellow pine/shrub, untreated
70-100
none
100%
0-100%
yellow pine/shrub, treated
20-100%
none
none
95%
none
1 pre-fire, consumed
Yellow pine-Douglas-fir-white fir, treated
90-100%
none
none
100%
none
none
0-100%
0%
1 snag, consumed
Fire Behavior Assessment Team
Overstory
Scorch
(%crown)
Torch
(%crown)
0%
none
mostly
none
none
none
none
20-80%
0-10%
50-70%
80-100%
none
0 to 90%
0-20%
50-95%
none
30-50%
0-20%
none
Antelope Complex
Fire Behavior Plot Photos
Adaptive Management Services Enterprise Team 7/14/07
Plot 2, pre- and post-burn. Low intensity surface fire at night, head fire upslope against the wind.
Plot 8, pre- and post-burn. Low intensity, backing surface fire at night.
Plot 11, pre- and post-burn. Low intensity, backing surface fire at night.
Plot 12, pre- and post-burn. Low intensity surface fire.
Plot 15, pre- and post-burn. Moderate intensity surface fire with some torching in midstory trees.
Plot 17, pre- and post-burn. Low intensity surface fire at night.
Plot 18, pre- and post-burn. Low intensity, backing surface fire.
Plot 19, pre- and post-burn. High intensity surface fire with torching in midstory and overstory.
Appendix B
Antelope Fire Temperature Graphs
Plot 2 Temperature
300
250
200
150
100
50
Figure B1. Plot 2 temperature data Y axis degrees Celsius X axis in time
:4
2
:1
3
21
21
:1
3
:1
2
:4
2
21
:1
2
:1
2
21
:1
2
:4
2
:1
1
21
21
:1
1
:4
2
21
:1
0
:1
2
:1
0
21
:1
2
0
Plot 11 Temperature
400
350
300
250
200
150
100
50
Figure B2. Plot 11 temperature data Y axis degrees Celsius X axis in time
7:
54
:3
4
7:
54
:0
4
7:
53
:3
4
7:
53
:0
4
7:
52
:3
4
0
Plot 12 Temperature
600
500
400
300
200
100
0
0
:0
36
:
10
0
:3
36
:
10
0
:0
37
:
10
0
:3
37
:
10
0
:0
38
:
10
0
:3
38
:
10
0
:0
39
:
10
Figure B3. Plot 12 temperature data Y axis degrees Celsius X axis in time
0
:3
39
:
10
0
:0
40
:
10
0
:3
40
:
10
Plot 17 Temperature
700
600
500
400
300
200
100
Figure B4. Plot 17 temperature data Y axis degrees Celsius X axis in time
23
:5
3:
25
23
:5
2:
55
23
:5
2:
25
23
:5
1:
55
23
:5
1:
25
23
:5
0:
55
23
:5
0:
25
23
:4
9:
55
23
:4
9:
25
0
Appendix C
About the Fire Behavior Assessment Team
We are a unique module that specializes in measuring fire behavior on active fires of all
kinds including wildland fire use fires, prescribed fires or wildfires. We utilize fire
behavior sensors and special video camera set-ups to measure direction and variation in
rate of spread, fire type (e.g. surface, passive or active crown fire behavior) in relation to
fuel loading and configuration, topography, fuel moisture, weather and operations. We
measure changes in fuels from the fire and can compare the effectiveness of past fuel
treatments or fires on fire behavior and effects. We are prepared to process and report
data while on the incident, which makes the information immediately applicable for
verifying LTAN or FBAN fire behavior prediction assumptions. In addition, the video and
data are useful for conveying specific information to the public, line officers and others.
We can also collect and analyze data to meet longer term management needs such as
verifying or testing fire behavior modeling assumptions for fire management plans, unit
resource management plans or project plans.
We are team of fireline qualified technical specialists and experienced fire overhead.
The overhead personnel includes a minimum of crew boss and more often one or more
division supervisor qualified persons. The team can vary in size, depending upon
availability and needs of order, from 5 to 12 persons. Our lead fire overhead is Mike
Campbell, Division Supervisor. We have extensive experience in fire behavior
measurements during wildfires, wildland fire use fires, and prescribed fires, having
worked safely and effectively with over 16 incident management teams.
We can be ordered from ROSS, where we are set up as “TEAM- FIRE BEHAVIOR
ASSESSMENT – FITES”. We can be requested by the following steps: 1) Overhead, 2)
Group, 3) Squad, and 4) in Special Needs box, “Requesting –Fire Behavior Assessment
Team- Fites’ Team out of CA-ONCC 530-226-2800.
You can also contact us directly by phone to notify us that you are placing an order, to
speed up the process. You can reach Jo Ann at 530-478-6151 or cell (only works while
on travel status) at 530-277-1258. Or you can reach Mike Campbell at 530-288-3231 or
cell (only works while on travel status) 530-701-3644. Or you can reach us through
Tahoe NF dispatch (530-478-6111), who has our home phone numbers as well. Do not
assume that we are not available if you call dispatch and we are already on a fire. We
have and can work more than one fire simultaneously and may be ready for
remobilization. For more information about the Fire Behavior Assessment Team (FBAT)
please see our website at http://www.fs.fed.us/adaptivemanagement/.
7/23/2007
Fire Behavior Assessment Team